J4 ›› 2013, Vol. 40 ›› Issue (1): 177-182.doi: 10.3969/j.issn.1001-2400.2013.01.030

• Original Articles • Previous Articles     Next Articles

Optimization scheme for outage performance in  a two-hop cognitive system

TANG Jingmin1;FENG Siquan2;LONG Hua1;LIU Zengli1   

  1. (1. Faculty of Information Eng. and Automation, Kunming Univ. of Science and Tech., Kunming  650500, China;
    2. Chongqing College of Electronic Eng., Chongqing  401331, China)
  • Received:2011-10-12 Online:2013-02-20 Published:2013-03-28
  • Contact: TANG Jingmin E-mail:tang_min213@163.com

Abstract:

By investigating the two-hop cooperative cognitive network in an overlay sharing(OS) mode, a cooperative detection strategy for the multiple cognitive user system is considered and outage probability formulation on the Amplify-and-Forward(AF) protocol is deduced. By optimizing the parameters such as sensing time and threshold, an optimization scheme has been proposed, which is proven to minimize the outage probability on the premise of guaranteeing fixed detection performance. Theoretical analysis and simulation result show that the optimal scheme can improve outage performance of the cognitive system and enhance transmission reliability of the cognitive network.

Key words: cognitive radio, overlay sharing, cooperative sensing, cooperative transmission, outage probability